Electrical annunciator



(No Model.)

T. W. LANE. Electrical Annunoiator.' .No. 234,993. Patented No v. 30,1880.

N. PETERS, PNOTOJ "Mann-12R, WASHINGTON, D C.

UNITED STATES ATENT OFFICE.

THOMAS WV. LANE, OF BOSTON, ASSIGNOR TO HIMSELF AND CHARLES WVILLIAMS, JR., OF SOMERVILLE, MASSACHUSETTS.

ELECTRICAL ANNUNCIATOR.

SPECIFICATION forming part of Letters Patent No. 234,993, dated November 30, 1880.

Application filed August 30, 1880.

T 0 all whom it may concern:

Be it known that I, THOMAS W. LANE, of Boston, in the county ofSuffolk and State of Massachusetts, have invented certain Improvements in Electrical Annunciators, of which the following is a specification.

This invention relates to electrical annunciators for use in hotels, telephone-exchanges, and elsewhere, by means of which a person remote from the central office may signal said oflice; and my invention consists in a novel device for such annunciators, whereby a metallic disk or shield is maintained in its normal position by gravity and thrown out by an electro-magnet acting to repel or attract a pivoted armature.

In electrical annunciators as ordinarily constructed the shield is held in its normal posiion by a catch or hook connected with the fiiield and adapted to enter an orifice in the armature of the magnet. The hold of the catch is necessarily slight, in order thatit may be released by the slightest movement of the armature. It often happens, therefore, especially after the mechanism becomes worn through use, that the catch fails to retain its hold upon the armature, and the shield falls by its own weight when no signal has been given. This serious objection to the proper working of the annunciator is entirely avoided by my invention, in which the shield is held in its normal position by gravity alone, and which provides an annunciator reliable in its action, simpler in construction, and less liable to get out of repair than those in common use.

In carrying out my invention I make use of the device which I will now proceed to specifically describe, reference being made to the drawings accompanying and forming part of this specification, in which- Figure 1 represents a side elevation of an electrical annunciator embodying my invention, Fig. 2 being a front View of the same. Fig. 3 represents a side View of a portion of the same apparatus with the signal-shield thrown out. Figs. 4, 5, 6, and 7 represent modifications.

In these figures the same letters of reference indicate the same parts.

In the form of my invention shown in Figs.

(No model.)

I, 2, and 3, M M represent an electro-magnet, such as is usually employed in apparatus of this class, rigidly attached to the base-plate I, which may be secured to any convenient point of attachment.

The poles N N of the magnet M M are provided with an armature, A, and the magnet itself is connected with the line by the wires d (I.

S represents a metallic signal disk or shield, pivoted at a to an arm of the base-plate I, and resting when in its normal position against the frame 0, as shown in Fig. 1.

The armature A is pivoted at b, and its lower extremity is in contact with one end of a pimp, which is movable horizontally through an oritice in the frame 0. The other end of the pin p is in contact with the back sideot' the shield S when said shield is in its normal position. i

It is obvious that so long as the armature remains in the position shown in Fig. l the shield S cannot fall, as, being slightly inclined backward against the frame (J, it will be held in its normal position by gravity.

The operation of my invention is as follows: The circuit being closed by pressure upon'a push-button or otherwise at any point on the line, an electrical current passing through the magnet M M will cause the armature A to be attracted to the poles N N. The movement of the armature upon its pivot b will cause its lower extremity to push the pin 19 outwardly against the shield S, throwing said shield outwardly, as shown by dotted lines, Fig. 3, until it falls by its own weight, thus giving the desired signal to the attendant.

The armature A is adjustable by means of the screw 8, which passes through an orifice in the upper part of the frame C. By means of this screw the oscillation of the armature upon its pivot 11 may be regulated and the degree of the backward inclination of the shield S when in its normal position determined, for the less the play of the armature A the nearer vertical will be the shield S, as it will be somewhat thrown out from the frame 0 by the pressure of the pin p, and the less the force required to cause it to fall completely over, as shown in Fig. 3. The apparatus may thus be adjusted to conform to the strength of thecurrent used to excite the poles of the magnet M M. Y

The form of my invention just described is intended for use in open circuits. When it is required to use my annunciator in closed circuits I make use of the modification shown in Figs. 4 and 5, both figures being side views of apparatus embodying my invention. In this modification the shield S is pivoted at a to a short lever, L, which is itself pivoted at c to the arm of the base-plate l. The inner extremity of the lever L is in contact with the lower end of the armature A, so that the outer extremity is slightly elevated when the armature is in contact with the poles of the magnet M M, as shown in Fig. 4, causing the shield S to be inclined backward against the frame (1, as in the form of my invention previously described.

In operation, the circuit being broken, the armature A falls away from the poles N N of the magnet M M, as shown in Fig. 5, its oscillation releasing the extremity of the lever L, which tips upon its pivot c, throwing out the shield S, which falls by its own weight.

Another modification of my invention is exhibited in Figs. 6 and 7, Fig. 6 being a side and Fig. 7 a top view. In this modification the magnet M M is placed vertically upon the base-plate I and the armature A is pivoted at b upon the frame 0. The shield S, inclined backward when in its normal position, as in the forms of my invention previously described, rests against a stop, F, which is pivoted at k to an arm, j, of the frame 0. A projection, l, of the stop F rests upon the armature A when the apparatus is in its normal position.

In operation, the armature A being attracted to the poles N N of the magnet M M, its oscillation rotates the stop F upon its pivot 70, thus throwing out the shield S, as shown by dotted lines in Fig. 6.

In electrical annunciators in open circuits it sometimes happens that the armature of the magnet becomes polarized, requiring to be forcibly detached from the poles of the magnet before the apparatus can be made operative. 111 my invention, as will be seen in Fig. 1, should this occur, the replacing of the shield S to its normal position after signaling will of itself remove the armature from the magnet, as the pressure of the shield against the pin 19 will force said pin inwardly against the lower extremity of the armature, thus oscillating it upon its pivot and removing its upper extremity from the poles N N.

Annunciators of the form herein described may be advantageously employed in telephone-exchanges for enabling an operator at any point upon the line to signal the central ofiice, and they are also applicable to any situation in which an electrical annunciator is required.

Having thus described my invention, what 1 claim, and desire to secure by Letters Patent, is

1. In an electrical annunciator, a magnet, a pivoted signal disk or shield held in its normal position by gravity, and an armature, in combination with a pin, stop, or lever interposed between said shield and armature, whereby by the operation of the armature the shield is mechanically impelled into signaling position, substantially as described.

2. In an electrical annunciator, a pivotal shield or signal-disk held in its normal position by gravity, and an armature, in combination with an interposed device movable by the operation of the armature to carry said shield or disk beyond its center of gravity, and so cause it to fall or act by its own weight, substantially as described.

3. The combination of an electro-magnet, a pivoted armature, a pivoted shield or signaldisk held in its normal position by gra ity, and apin or equivalent device interposed between the shield and armature, whereby when said armature becomes polarized the returning of the shield into its normal position so actuates the interposed device as to mechanically depolarize said armature, substantially as described.

4.. In an electrical annunciator, an armature and a signal-disk, in combination with an interposed device operated by the armature to effect the giving of a signal and actuated by the signal-disk to depolarize the armature, substantially as described.

5. In an electrical annunciator employing an open circuit, the combination of a magnet. an armature, a shield or signal-disk adapted to be held in its normal position by gravity, and a device operated positively through the armature by the closing of the circuit to mechanically move such shield or signal-disk beyond its center of gravity to cause it to give the signal or alarm, substantially as described.

6. In an electrical annunciator employing a closed circuit, the combination of a magnet, an armature, a shield or signal-disk adapted to be held in its normal position by gravity, and a tripping device interposed between the armature and shield and actuated by the breaking of the circuit to cause said shield or signal-disk to move into a position to act by its own weight to give the signal or alarm, substantially as described.

In testimony whereof I have signed my name to this specification, in the presence of two subscribing witnesses, this 27th day of August, A. D. 1880.

THOS. WV. LANE.

Witnesses H. G. WADLIN, W. OLIMo. 

